The US DMCA isn't a law you need to comply with or not comply with. Anybody can choose to ignore it and not register a DMCA agent. It will save them $105.
It's an insurance policy.
If you don't think you need to be insured against being sued in US courts for copyright infringement, then you can ignore it.
But, as I mentioned in my article, plenty of foreign companies *are* registering -- it's a small fee, and you get a lot of protection.
In particular, if I was investing in a commercial grid with customers and content from all over the world, I'd want them to register, to have that insurance in place.
